The present invention relates to a heat pump type air conditioner for a vehicle, and more particularly to a vehicular air conditioner which executes a heating by operating a refrigeration cycle thereof.
Generally, an air conditioner employed in a vehicle is arranged to execute a heating operation by using a heater core circulating engine coolant and to execute a cooling operation by using a refrigeration system.
However, when an engine of the vehicle is started under a condition that an outside air temperature is considerably low, it is necessary to take a predetermined time period until the engine coolant is warmed at a temperature such as about 50xc2x0 C. so as to be applied in the heating operation. Furthermore, if the engine is operated under idling condition or low-load condition, the temperature of the engine coolant tends to be kept at a temperature insufficient for a heater core to be applied to the heating operation.
It is an object of the present invention to provide a heat pump type air conditioner which quickly and sufficiently executes the heating operation by employing the refrigeration system of the air conditioner.
A first aspect of the present invention resides in a heat pump type air conditioner for a vehicle which executes a heating operation and a cooling operation according to a temperature condition. The heat pump type air conditioner comprises a compressor applying workload to refrigerant. An external heat exchanger is connected to an outlet of the compressor. A first flow control valve is connected to a refrigerant outlet of the external heat exchanger. An auxiliary internal heat exchanger is connected to an outlet of the first flow control valve. A second flow control valve is connected to a refrigerant outlet of the auxiliary internal heat exchanger. A main internal heat exchanger is connected to an outlet to the second flow control valve. A refrigerant outlet of the main internal heat exchanger is connected to an inlet of the compressor. An air delivering section flows air through the main and auxiliary internal heat exchangers and delivers the air to a passenger compartment of the vehicle.
A second aspect of the present invention resides in a heat pump type air conditioner which executes a heating operation and a cooling operation according to a temperature condition. The heat pump type air conditioner comprises a compressor applying workload to refrigerant. An external heat exchanger is connected to an outlet of the compressor. An auxiliary internal heat exchanger has a first port and a second portion and is arranged such that a cross sectional area of a refrigerant passage of the auxiliary internal heat exchanger is gradually increased from the first port to the second port. An expansion valve is connected to the first port of the auxiliary internal heat exchange. A refrigerant passage switching section selectively establishes a first refrigerant passage state for flowing the refrigerant from the expansion valve and the first port to the second port and a second refrigerant passage state for flowing the refrigerant from the second port to the first port and the expansion valve. A main internal heat exchanger is connected to one of the first and second ports from which the refrigerant is delivered. The refrigerant outlet of the main internal heat exchanger is connected to an inlet of the compressor.